Oil-burning furnace



Aug. 3 1926.

1,595,01 1 LITHMAN OIL BURNING FURNACE Filed Dec. 8, 1923 3 Sheets-Sheet 1 M 260 9061] Iw'/vman 29 Marn /s.

Aug. 3 1926.

1,595,011 LITHMAN OIL BURNING FURNACE 1923 3 Sheets-Sheet 2 1 Filed Dec. 8,

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Aug. 3 1926.

1.. LITHMAN OIL BURNING FURNACE Filed Dec. 8, 1923 3 Sheets-Sheet 5 260 05a] Iii/amen E aq'tww yw Patented Aug. 3, 1926.

UNITED STATES LEOPOLD LITHMAN, OF WORCESTER, MASSACHUSETTS.

OIL-BURNING FURNACE.

Application filed December 8, 1923. Serial No. 679,491,

This invention relates to a heating furnace for heating houses, blocks and the hke heated by means of oil.

The principal objects of the invention are to provide a furnace capable of use for heating a house or building in connection with a steam boiler, hot water system or air which can be heated by using the cheapest forms of crude oil; to provide means for blowin the liquid fuel into the burner under a force draft; and to provide an improved mechanism for feeding the oil from a. pump into the outlet from the blower so as to regulate the amount, and secure uniformity, of feed.

Further objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawings, in which Fig. 1 is a plan of the fire box of a furnace with a preferred embodiment of this invention applied thereto and shown partly in horizontal section;

Fig. 2 is a vertical sectional view on the broken line 22 of Fig. 1 showing certain parts in elevation;

Fig. 3 is a wiring diagram showing the electrical connections;

Fig. 4 is a longitudinal sectional View of the fuel regulating or equalizing cup;

1 1g. 5 is a sectional view on the line 55 of Fig. 1 showing the drain outlet of the fire box;

Fig. 6 is a sectional view through the center of the fuel pipe along the-line 6-6 of Fig. 1 showing the device for automatically shuttin off the oil when the draft stops; and

Fig. 7 is a lon itudinal view partly in section of the detai s of the means for preventing the draft blowing back into the gas pipe connected with the pilot light. I

I have shown the invention as being so laid out as to have it all run by a motor 10 connected with the electric mains as shown in Fig. 3 regulated through a thermostat 11, and electric steam gauge 12 whenever the device is used for a steam heating plant, which is the principal way in which it is intended to use it. Directly mounted on the shaft 13 of this motor is ablower shown as located in a casing 14.

Connected with this shaft is a train of gears located in a casing 15 for driving a pump shaft 16 at a slower speed. This shaft drives a pump 17 which may be of any desired type. This pump takes crude oil through an inlet pipe 18 from a supply tank 19 and discharges it through a pipe 20 into an equalizing cup 21. This cup is shown as of a simple form of casting having a cover out through the supply main 27 or through the return 28 back into the tank 19. This return 28 is provided with a valve 29 which can be opened and closed with a wrench.

The supply main 27 is provided with a hand operated valve 30 for controlling its operation and it is also provided with an automatically controlled valve 31, the purpose of which will be described later. It discharges at 32 into the outlet of the blower 14 and the blast of air through the outlet into the fuel pipe 33 takes up the oil, aspirates it and delivers it in what is practically a fine mist into the fire box 34 within the furnace 35. As the air and oil pass along in the form of a spray they naturally operate on a vane 36 pivoted on a central rod 37 in the pipe 33 and held down normally by a weight 38 on the vane. When this blast starts it will turn this vane up toward the position shown in dotted lines in Fig. 6 and therefore turn the arm 39 mounted on the projecting end of the shaft 37. This arm operates the arm 40 of the valve 31 and tends to 0 en that valve in proportionto the intens1ty of the blast until the weight 38 moves up to. the dotted line position at full pressure. This constitutes automatic means for opening the oil supply and for regulating it at all times in proportion to the air pressure. When the blower stops the valve 31 is closed automatically and any oil flowing will be directed back to the tank;

The blast of air and oil in fine particles is delivered into the circular fire box 34 which is provided with a lining and against a casting 41 therein which I call a hot spot'because the fuel is directed toward its center and it is heated up to the highest point of any part of the furnace. This casting is of heavy design simply laid on the flat bottom of the fire box. It is placed there to hold the heat and protect the back of the fire box which otherwise would receive the full blast of the flame. It tends to confine the heat in a space near the center of the fire box on account of its pro'ectmg upper lip 42. It is readily removable for replacement.

If the pilot burner 53 goes out any 011 that is not-burned and that'collects in the substantially horizontal bottom of the fire box will run into-a recess 43 and out through a pipe 44. This short section of p1p1ng 1s connected with a waste pipe 45 which is provided with a vertical venting tube 46 appear later. When it engages the pivoted lever 51 it turns it as indicated in Fig. 3

I so that the end of that lever is removed from contact with a conducting terminal 52 in These parts const1-.

the electrical circuit. tute a safety switch. It Wlll be seen that i when the pan 47 descends the whole circuit is broken and boththe blower and the pump are stopped.

The efi'ectof the closing of the valve 49 also is to shut ofi' the gas flowing through the pipe 50 into a pilot burner 53. This pilot burner discharges a flame, Wl'llOh is 1ntended to be constantly lighted, against a baflle plate 54 which directs it so that it is sure to light the oilthat is brought into the fire box. This is lighted all the time except when the pan descends and turns 1t I find that the blast of air coming into the fire box tends to create a back pressure in the gas pipe 50. For the purpose of overcom-- mg this I extend the pipe back at 55 to a point in the casing 14 of the blower so that a current of air is forced through this pipe 55 and through a casing 56 at theend of it into openings 57 in the casing of the valve 49. Thus, at all times when the blowor is operating there is a draft, but only a slight one, through the gas pipe toward the burner 53. This is sufficient to prevent the pressure inthe firebox forcing the gas back in the pipe 50 and putting out the pilot light.

On account of this combination of parts it will be seen that the pilot light burns con stantly, always ready to ignite the oil when the motor is started and that the only thing that can put it out is the filling of the pan 47 with oil drained out of the fire box. It will also be seen that this not only automatically turns off the pilot burner but also stops the motor and therefore the blower and pump.

' I have already described the automatic closing of the valve 31 when the draft stops in the pipe 33 and the circulation of the oil through the pump returns the surplus to the storage tank 19. The construction of the fire box with the hot spot is an important feature as described as it tends to reduce the noise of the flame and confines the heat and retains it so that the furnace is more uniformly and more evenly heated than it would be by simply letting the flame play on the rear wall of the fire box without providing this hot spot.

The whole device is inexpensive to manufacture and install and simple to maintain and operate. It is capable of burning low grades of crude oil and does not require any experienced person to operate it.

'Although I have illustrated and described only a single form of the invention I am aware of the fact that modifications can be made therein by any person skilled in the artwithout departing from the scope of the invention as expressed in the claims. Therefore I do not wish to be limited to all the details of construction or to the particular arrangement of parts herein shown and described-but what I do claim is 1. In a liquid fuel burning system, the combination with a motor and a blower directly connected therewith, of a pump. oper- .ated by' the motor at a slower speed, a discharge pipe from the pump, an equalizing cup connectedwith the discharge pipe and comprising a spring-pressed automatic valve which will open to let the fuel into the cup only when the fuel pumped into it reaches a predetermined pressure, a supply main from said cup directed into the outlet of the blower, and a return pipe from the bottom of the cup for returning the surplus fuel to the source of supply.

2. In a liquid fuel burning system, the combination with a motor and a blower connected therewith, of a pump, a liquid fuel supply tank connected with the pump, a discharge pipe from the pump, an equalizing cup connected with the discharge pipe and having an automatic inlet valve therein arranged to close and prevent entrance of fuel into the cup under low pressure, a discharge pipe from said equalizing up back into the oil tank, and a supply main from said cup directed into the outlet of theblower.

In testimony whereof I have hereunto affixed my signature. LEOPOLD LITHMAN. 

